The Java EE 5 Tutorial

Creating Deployment Descriptors for Message-Driven Beans

By using resource injection and annotations, you avoid having to create a standard
ejb-jar.xml deployment descriptor file for a message-driven bean. However, in certain situations you
still need a deployment descriptor specific to the Application Server, in the file
sun-ejb-jar.xml.

You are likely to need a deployment descriptor if the message-driven bean will
consume messages from a remote system. You use the deployment descriptor to specify
the connection factory that points to the remote system. The deployment descriptor would
look something like this: